We have previously reported the use of subtraction PCR to identify genes downregulated in B lymphomas and from these studies observed methylation-dependent transcriptional silencing of the polo-like kinase Snk/Plk2 (Syed et al, 2006), which showed a strong, but not absolute, selectivity among B cell neoplasias, for BL. This evidence concerns the gene PLK2 and Burkitt lymphoma.